1. Field of the Invention
The present invention relates to a robot system capable of performing regulated movements, and more particularly, to various types of robot systems which operate within the same activity space as that of a human.
2. Description of the Related Art
In a related-art robot system, a mechanism system having a skeletal frame made of metal or resin is actuated by means of motors, actuators, or engines, which employ various types of power. A required posture of a robot system is maintained through several steps. First, information obtained by way of various internal and external sensors is processed through use of a controller. Here, the controller is mounted on a robot system main unit or outside the main unit and can exchange information with the robot system main unit. Next, restoration force stemming from gravity is utilized by use of a balance controller which issues required instructions to individual drive sections and shifts a corresponding weight, or by loading into a bottom ballast corresponding to a weight sufficient for canceling out a shift of center of gravity in the upper potion. By virtue of these operations, the system requires complex information processing. Further, the robot system is heavy and rigid and poses danger to a human when operated within the same activity space.
In order to prevent such a danger, the robot system must be made slim and slender. However, realization of a slender robot system is difficult in terms of preservation of shape of a structural body. Robot systems, including a walking robot, require integration and appropriate control of a large number of sensor and drive systems for effecting preservation of system posture, stable self-support, and movements. Therefore, a heavy load is imposed on an information processing system, in turn rendering the information processing system bulky and involving consumption of massive amounts of energy. Further, restrictions are imposed on the weight of the overall robot system. Particularly, considerable influence is imposed on a self-supporting system or autonomous system. When restoration force for effecting an attitude control is dependent on a restoration moment stemming from gravity, a robot system is equipped with ballast, thereby rendering the total weight of the robot system heavy.